Codec to use for HD?

I need help figuring out which codec is best for best picture quality for size. I figure (based on the wmv hd website) that 8000Kbps is good for 720p and 10000kbps is good for 1080p. I've been taking 200Mbps 1280x720 game footage and trying to compress it down, but by using the Windows Media Video 9 I've been unable to get it to 8000Kbps and have it look acceptable. Also I've been having motion artifact problems that I don't know how to fix. The closest I could get it where I'd consider it acceptable to the HD name was 12000Kbps, but it still had kind of a blurryness with motion or when the camera turns quickly. When you got 20 minutes of video and your adding 1Mbps like nobodies business, it jacks the file size like there's no friday!

I really want to do whatever I can to keep this looking really good and make it as small as possible.